1. Field of Invention
This invention relate to finishing devices and sorting devices for printers and/or copiers.
2. Description of Related Art
Devices that process sheets of paper, such as high-speed photocopiers, often require finishing operations to be performed. Such a finishing device causes the paper sheets to be deposited in manner either selected by the user or by a default fashion.
Many finishing devices and sheet stacking devices are known in the sheet handling equipment industry, involving different sheet ejection points for sheets of varying lengths. Conventional finishing devices convey paper sheets through a gate selected from a series of gates based on the length of the sheet being conveyed. Transporting the sheets to a compiling area in the finishing device typically requires redundant drive devices. In addition, a sheet constraint may be needed to align the trailing edge of the sheet as and/or after it passes through the appropriate gate.
In addition to multiple gate selectors, separate sheet constraints are employed in commercially available finishing devices. Consequently, a large number of moving components are required to complete a sheet finishing process, resulting in reduced reliability and shorter service life than desired.
In most downhill compiling systems, a different sheet ejection point is required for sheets of different lengths. Such systems in finishing and sorting devices typically use a series of gates to direct a sheet along a paper path. The sheet passes through an appropriate gate that is selected and actuated based on the length of a sheet being conveyed.
This invention provides devices and methods for opening a paper gate by a gate cam.
This invention further provides devices and methods for pushing a sheet by a paddle connected to the gate cam.
This invention also provides devices and methods for maintaining the gate open by the gate cam for a range of paper lengths.
This invention separately provides devices and methods for moving a gate cam by a stepper motor.
This invention separately provides devices and methods for moving the gate cam along a rail.
In various exemplary embodiments of the methods and devices according to this invention, a paper sheet entering a finishing device passes through a gate selected and controlled by a combined paper path selector, actuator and sheet constraint structure, which is referred to below as a combined gate system. In various exemplary embodiments, the selected gate is actuated by moving a sliding cam unit along one or more guide rails disposed along at least one side of the finishing device.
Upon entering into the finishing device, the sheet is transported along nip rollers until passing through the appropriate gate, which has been selected and opened based on the size of the sheet being conveyed by the combined gate system.
In various exemplary embodiments, the sliding cam unit includes a gate cam to raise a follower for actuating the gate. In various exemplary embodiments, the gate cam includes a forward ramp for a head surface, a horizontal plateau, and a rearward ramp for a tail surface.
In various exemplary embodiments, a paddle on the combined gate device constrains the sheet from becoming misaligned after passing through the combined gate device.
In various exemplary embodiments, the movable cam is connected to a sliding cam unit that moves along the guide system or structure by a drive system. In various exemplary embodiments, the drive system includes a stepper motor to move a driver belt that is connected to the sliding cam unit.
In various exemplary embodiments, the sliding cam unit travels over the one or two guide rails on polymer shoes or sliding structures. The sliding cam unit includes a gate cam formed as a wedge from molded plastic. In various exemplary embodiments, the rail and shoe materials are low friction materials.
The combined gate system enables precisely timed and positioned control of a sheet passing through to a finishing station. By combining gate actuation allowing a sheet to pass through with a paddle for preventing backlash of a sheet, the combined gate system improves reliability with fewer moving parts.
These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.